Humidification arrangement for a respiratory apparatus

Abstract

A humidifying apparatus utilizing a semi-permeable membrane portion within a gas conduit where the direction of gas flow within a central lumen is given by an arrow. The humidification apparatus has a helical configuration for the semi-permeable membrane portion, a structural reinforcing member or members, a water channel and a heating element. The helical configuration of an outer wall may be similar to conventional conduits that are in common use in respiratory apparatus. Thus the humidification apparatus may be readily substituted into existing respiratory device by exchanging the gas conduit.

The invention claimed is: 
     
       1. A humidifier configured to humidify and convey a flow of respiratory gas, the humidifier being in the form of a flexible, tubular conduit and comprising:
 a central lumen that is part of the conduit and has an open first end and an open second end, the central lumen being configured to convey the flow of respiratory gas to a patient's airways; 
 a liquid water retainer that is part of the conduit and is configured to retain liquid water, the liquid water retainer being located outside any flow of respiratory gas; and 
 a heater that is part of the conduit and is configured to heat the liquid water in the liquid water retainer to generate water vapor. 
 
     
     
       2. A respiratory apparatus configured to provide positive pressure gas to a patient's airways, the respiratory apparatus comprising:
 a positive airway pressure device configured to generate a flow of positive pressure gas; 
 a patient interface configured to engage the patient's face and be in communication with the patient's airways; and 
 the humidifier according to  claim 1 , the humidifier being configured to convey the flow of positive pressure gas to the patient interface. 
 
     
     
       3. A humidifier in the form of a flexible, tubular conduit and comprising:
 a first portion that is part of the conduit and is configured to convey gas through the humidifier, the first portion comprising a central lumen with an open first end and an open second end; 
 a second portion that is part of the conduit and surrounds the first portion and positioned to be outside a flow of any gas conveyed through the humidifier, the second portion comprising a liquid water retainer and a heater configured to vaporize liquid water retained within the liquid water retainer; and 
 a flexible outer wall housing the first and second portions. 
 
     
     
       4. The humidifier according to  claim 3 , wherein the central lumen is defined by a flexible, gas permeable inner wall configured to facilitate a flow of water vapour from the liquid water retainer to the central lumen. 
     
     
       5. The humidifier according to  claim 4 , wherein the gas permeable inner wall is configured to prevent a flow of liquid water from the liquid water retainer to the central lumen. 
     
     
       6. The humidifier according to  claim 3 , wherein the heater is positioned inside the liquid water retainer and comprises a plurality of heating elements extending along a length of the liquid water retainer. 
     
     
       7. The humidifier according to  claim 6 , wherein the plurality of heating elements define a plurality of channels configured to receive a flow of water from a water inlet. 
     
     
       8. The humidifier according to  claim 3 , wherein the liquid water retainer comprises a plurality of water tubes forming one or more portions of a flexible, gas permeable inner wall defining the central lumen. 
     
     
       9. The humidifier according to  claim 3 , wherein the liquid water retainer comprises a wick and/or a capillary action device. 
     
     
       10. A respiratory apparatus configured to provide positive pressure gas to a patient's airways, the respiratory apparatus comprising:
 a positive airway pressure device configured to generate a flow of positive pressure gas; 
 a patient interface configured to engage the patient's face and be in communication with the patient's airways; and 
 the humidifier according to  claim 3 , the humidifier being configured to convey the flow of positive pressure gas to the patient interface. 
 
     
     
       11. The respiratory apparatus according to  claim 10 , wherein the positive airway pressure device comprises a liquid water reservoir configured to supply water to the liquid water retainer. 
     
     
       12. The respiratory apparatus according to  claim 11 , wherein the liquid water reservoir and the liquid water retainer are configured to be in a loop arrangement so that liquid water is circulated between the liquid water retainer and the liquid water reservoir. 
     
     
       13. A humidifier configured to humidify and convey a flow of respiratory gas, the humidifier being in the form of a flexible, tubular conduit and comprising:
 an air inlet, an air outlet and a central lumen that is part of the conduit and extends from the air inlet to the air outlet, the central lumen being configured to convey the flow of respiratory gas to a patient's airways; 
 a liquid water retainer that is part of the conduit and is configured to retain liquid water, the liquid water retainer having a closed first end and a closed second end, a liquid water inlet being located at the second end; and 
 a heater that is part of the conduit and is configured to heat the liquid water in the liquid water retainer to generate water vapor. 
 
     
     
       14. The humidifier according to  claim 13 , wherein the central lumen is defined by a flexible, gas permeable inner wall configured to facilitate a flow of water vapour from the liquid water retainer to the central lumen. 
     
     
       15. The humidifier according to  claim 14 , wherein the gas permeable inner wall is configured to prevent a flow of liquid water from the liquid water retainer to the central lumen. 
     
     
       16. The humidifier according to  claim 13 , wherein the heater is positioned inside the liquid water retainer and comprises a plurality of heating elements extending along a length of the liquid water retainer. 
     
     
       17. The humidifier according to  claim 16 , wherein the plurality of heating elements define a plurality of channels configured to receive a flow of water from the liquid water inlet. 
     
     
       18. A respiratory apparatus configured to provide positive pressure gas to a patient's airways, the respiratory apparatus comprising:
 a positive airway pressure device configured to generate a flow of positive pressure gas; 
 a patient interface configured to engage the patient's face and be in communication with the patient's airways; and 
 the humidifier according to  claim 13 , the humidifier being configured to convey the flow of positive pressure gas to the patient interface. 
 
     
     
       19. The respiratory apparatus according to  claim 18 , wherein the positive airway pressure device comprises a liquid water reservoir configured to be connected to the liquid water inlet and supply water to the liquid water retainer. 
     
     
       20. The respiratory apparatus according to  claim 19 , wherein the liquid water reservoir and the liquid water retainer are configured to be in a loop arrangement so that liquid water is circulated between the liquid water retainer and the liquid water reservoir.